You did not make a mistake taking honors classes! You will become a better student by being challenged. Taking the easier route to get all A’s will actually not prepare you best - we all learn when we are pushed, and make some mistakes - colleges know this too. Selective colleges want to see you take advantage of the challenging courses offered by your high school. It sounds like you are succeeding in these courses. B’s in your first semester of high school are very understandable. Talk to your teachers and get feedback on the areas that you are struggling in. Ask them for tips on how to study more efficiently. Focus on your current work and activities and doing the best that you can. The more you learn about yourself and the type of student you are, the more prepared you will be to plan well for college.
You have not shut yourself out of Ivy League schools - but Ivy League schools are actually not the best for everyone - even for every “qualified” student.
You are in 9th grade now- you are not applying for college yet. Use this time to be in 9th grade! Then, when it is time to apply to college - use what you have learned about yourself to find a college that is a great match for you. There are lots of amazing schools with so many opportunites!